This is an attempt to build a data link for the fx5800P to be able to transfer data and store it on a PC.
As a start I measured the voltage levels of thetransmitted signal from the 2.5mm jack. The levels where 0-2.7v, so to connect the calc to PC using a MAX232 based cable see this link http://www.casiocalc...=2686&hl=max232
I needed a voltage level of 0-5V. Thus I constructeda simple level converter based on the LM339 comparator which was in my reach. Fig.1 shows the schematic of the level converter, Fig.2 and Fig.3 shows the transmittedsignal before and after the level converter. Fig.4 is the 2.5mm Jack.
The next step is to figure out the protocol that fx5800P use. I needed the baud rate, data bits, parity bits, stop bits to connect the calc to PC HyperTerminal or any other s/w to analyze the outgoing signals using COM port (RS232 serial port). Any suggestions?
Edited by M.Yasser, 09 July 2011 - 11:52 PM.